Paper manufacture



1932- J-. J..ccoN oR 1,858,291;

' PAPER MANUFACTURE I 7 Filed 001;. 9. '1929,

INIgENTOR BY Wi -Q Patented July 19, 1932 UNITED STATES PATENT OFFICE JAMES J. OCONNOR, OF CHILLICOTHE, OHIO, ASSIGNOR TO THE .MEAD PULP AND PAPER COMPANY, OF DAYTON, OHIO A CORPORATION OF OHIO i l PAPER MANUFACTURE Application filed October 9, 1929. Serial No. 398,404.

This invention relates to the manufacture of paper, and particularly to the treatment in the manufacture of better grades of paper,

such for example as those known inthe trade as book paper, to incorporate in the formed sheet a certain amount of filler which usually consists of'finely ground clay, or other similarly acting substances. This invention relates particularly to the manufacture of paper in which filler is incorporated.-

One of the principal objects of this invention is to provide a method of introducing and intermixing the various ingredients which go to form a finished 'web of paper, which gives an improved product, provides'better operating conditions, and permits of improved recovery of materials which would otherwise be wasted.

Another object of the invention is to provide'a method of introducing and intermixing a fine-grained solid material such as filler in the fibrous stock, and of filtering liquid withentrained solids drained and removed from the paper under formation.

Another object of the invention is to provide apparatus for carrying out the above method.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawing and appended claims. 7

The drawing illustrates diagrammatically a preferred embodiment of apparatus for practicing this invention; but. inasmuch as the invention is practiced through "the utilization of conventional machinery generally found in the paper making art, details of construction thereof are not disclosed.

Referring to the drawing, a conventional beater is indicated at 10 'which serves toproperly condition the pulp and mix ingredients added to the fibrous stock therein.

The treated fibrous stock is then passed to a beater chest 11, which is usuallydirectly beneath'the beater so that. the stock may flow thereinto by gravity. From the beater chest the stock is pumped, or flowed, to a large machine chest 12 generally provided with agitating mechanism (not shown), which serves as a storage chest for the furnish to be supplied to a particular forming machine, or group of machines utilizing the same furnish.

, From the machinechest 12, the stock is withdrawn by a pump13 and forced through a pipe '14 into the central compartment 15 of a conventional stuff box 16 provided with partitions 17 and 18 dividing the stuff box into the central compartment 15 and outer compartments 19 and 20. The partition 17' functions as .an overflow bafile, the excess stock pumped to the stuff box and overflowing this partition being returned by the. plpe 22 to the machine chest 12.] The partition 18 is provided with a sliding gate or weir 23 which is adjustable to provide for controlled flow of the stock into the compartment 20, whence it feeds by pipe 25into a conventional Jordan .01 other refining engine 26 serving properly condition the stock for formatlon.

The discharge from the jordan 26 passes by pipe 30 into a series of rifiles 31,.whioh generally comprise a flow passage having a plurality of upstanding baflies 32-providing collecting troughs where any heavy particles, inadequately refined stock, or impuri .ties may separate out.- Suitable screemng' apparatus 34 is generally positioned beyond- I the riflles, as an additional precaution to. re'- move impurities and unrefined, material. The stock from the screens passes into the: head box 35 of a conventional formingvmachine 36-where a traveling web of, paper-is formed.

As illustrating a preferred form of apparatus,"a Fourdrinier machine is shown having a breast roll end 37 anda couchroll end 38 with a plurality of table rolls 39 and suction boxes 40 over which, passes an endless forming wire 41. It is to be understood that other types of conventional forming machines, as well as other types of preliminary treating and refining apparatus may be used in the practicin ref this invention.

'When the fibrous stock ows from the inlet l 2 43 of the head box 35 onto the traveling wire 41, the water in the stock rapidly drains through the wire leaving the fibrous materlal and other ingredients in the form of a web thereon. The web is removed from [the couch or suction'roll end 38 of the forming machine and passes to conventional drying machinery such as presses, driers, etc. (not shown). is v The initial rush of water draining from the web under formation through the traveling forming wire 41 is so rapid that a portion of filler, short fibers, and the like is washed through or withdrawn from the web, to be thus entrained in this liquid drained or removed from the web at the forming machine. In order to prevent wasteand to recover these materials, a collecting chamher or wire pit and couch chest 45 is provided beneath the forming machine. A por tion of the liquid draining through the wire is also collected-in tray boxes 46, and from there removed by pipe 47 and pump 48 and forced through pipe 49 back into the flowing stock stream passing to the forming machine. In the conventional practice, the stock passes through the jordan at a consistency of.ar0und 5%, while the preferred consistency for introduction onto the formmg machine is generally around 1 to 1%. The liquid draining through the Wire and collected in the tray boxes 46 is thus economically utilized to make down the thicker stock which has passed through the jordan to the desired lowconsistency which is best suited for the forming machine. This dilution liquid is prefer-ably added as shown at the riflies 31 to provide for adequate intermingling with the stock prior to its passage onto the formin machine. The filler, short fi ers, and other solid ingredients collected with the liquid in the tray boxes 46 is thus returned to the fibrous stock. In order torecover the solid ingredients entrained in the liquid collected in the wire pit and couch chest 45, this is pifinped by a pump 50 through pipe 51 to a conventional filter 52, such as a rotary vacuum filter. Very satisfactory results are secured with a filter known in the art as the Oliver filter, or with a United filte This comprises generally a vat 53 into which the liquid is pumped, and rotatably mounted in suitable hearings and dipping in the liquid "within'the vat 53 is a rotary perforate screen or series of screens 54. This rotary screen is divided into compartments of definite suction area, which are connected through a hollow trunnion of the rotary screen and a pipe 55 to a suction chamber 56, the upper portion of which is connected by a pipe. 57 to a conventional vacuum pump 58, whereby uniform suction is produced in the various compartments. The suction causes the liquid to pass through screeninto surface of the screen. 7 i

Inasmuch as solid ingredients in this liquid escaping from the forming machine form a very small percentage thereof and as the fibers are. quite short, the entrained filler and some short fibers tend to escape through the perforated screen with the liquid and thus be wasted. In order to minimize such waste, a portion ofthe fresh fibrous stock containing a high percentage of long fibers is continuously withdrawn from a source of supply of the furnish for the forming machine 36 and passed'to the filter 52. As shown, a pump 60 serves to continuously withdraw fibrous stock through pipe 61 from the machine chest 12and pass it through pipe 62 to the vat 53 of the filter 52. This serves to introduce suflicient fibrous material into the vat 53 to form an effective filter mat on the rotary screen 54, which mat then efi'ec tively removes fine fiber and filler from the circulating liquid or white water removed from the forming machine 36.

As the screen 54 rotates carrying the A filtered material above the liquid level within the tank 53, sprays of wash water are directed thereon from spray pipes 64 to wash the recovered materials. As the, filter continues to rotate, the material which has thus been washed and thickened arrives at an area which is not subject to suction, and at this point a flexible scraper member 65 scrapes the material from the filter onto a chute 66 down the operating cost of the plant, a portion of this white water may be passed through pipe 7 0 controlled by valve 71 to the showers 72 which serve to wash the wire 41.

Another portion may be passed by pipe. 73 controlled by valve .74 to the beater 10 to make down the stock therein to the desired v consistency for beating, and the excess may be discharged to sewe q It isthe usual practice, in manufacturing a filled paper. to introduce the filler, and

"other ingredients such as size, alum, and the like,into the beat-er along with the fibrous material. I have discovered that material economy may be effected by adding the filler subsequent to the beating operation. It is to be noted that the fibrous stock is passed from the machine chest 12 to the forming machine36 in a continuously'flowing stream.

I preferto continuously add the filler into this continuously flowing stock stream prior to its introduction onto the forming machine. In actual practice, very satisfactory results have been secured where the filler is made up into a suspension in water of controlled con.- centration, and this filler suspension screened and pumped through pipes controlled by valves and continuously discharged in controlled amount into the flowing stock stream. A saving in labor results due to the elimination of measuring weighed amounts of filler to the beater 10 for each batch being treated, as in the conventional practice. According to the present invention, after the valve controlling the pipe line for the filler suspension has once been adjusted, no further manual control or labor is necessary to effect the desired control of the addition of this material to the furnish.

I have further discovered that it is preferable to add the filler beyond the machine chest 12, such as at the riflles 31. Where such filler is added continuously to the stock stream as by a pipe 7 6 controlled by a valve 77 shortly prior tothe flowing of the stock stream upon the wire, I have found that it is possible to increase the filler content of the furnish to as high as by weight (if filler,

or even higher, and still make a very satisfactory sheet on the forming machine at a high rate of speed. In theconventional practice where the filler is added at the beater, a

'slower sheet is produced, and it has been found practically necessary to limit the filler content to about 20% by weight to secure satisfactory operating conditions. The increase in the amount of filler by the practicing of my method efi'ects an economy in the furnish, inasmuch as filler is cheaper than fiber. A superior product results inasmuch as increased percentages of filler improve the printing quality and opacity of the sheet,

which is quite important in printing or,book paper. 1 I have also discovered thatmaterially improved recoveryof the solids in the liquid draining through the forming wire or otherwise removed by the forming machine .36 is effected by by-passing fresh fibrous stock to.

the'filter 52. prior to the introduction of this shown inthe drawing, the fibrous stock is withdrawnfro-m' the machine chest '12 by the pump prior to the introduction of filler therein .by the pipe 76. 'The, increased filter ing effectiveness is believed -'due to the fact that the material by-passedthrough pipe 62 from the machine chest 12 to the filter 52 does not contain the usual percentage of filler, but

consists primarily of fibrous stock contain'ing a large percentage of long fibers whichform a very effective filter mat on the screen 54:,

so that an inappreciable proportion of. this by-passedstock is lost by escape through the filter, The efiluent loss, that is, the solid in Thus as gredients escaping through the filter, is not onlyconsiderably reduced bythe practicing of my method, but also the capacity of the recovery filter is increased enablinganincrease in the rate of filtering. I This permits the forming machine to be operated at a generally used to further reduce the cost of the furnish. The filler content of the broke and old paper stock however, only represents a minor proportion of the filler supplied to the furnish. The main supply of filler is then added in accordance with my invention beyond the point at which the fibrous stock is withdrawn or by-passed to the. recovery filter, with material improvements 'in operation and resulting product, and in recovery of ingredients in the white water. If desired, the pulped broke or oldpaper stock may beadded to the furnish beyond the point where fibrous stock is by-passed to the recovery -filter, as the broke and old paper stock does not require thedegree of conditioning treatment needed for fresh fibrous stock ,linasmuch as they had previously been effectively separated into their ultimate fibers when originally made into paper. Or a' portion of the fibrous stock for a machine furnish may be by-passed to the recovery filtel of that machine at other points in the systemprior to theintroduction of the broke and old paper stock therein.

While the invention is particularly described in connection with the use of filler, it is to be understood that the invention is also applicable toother fine-grained solid materials which are incorporated in papermaking stock and which would tend to escape through a filter'in the manner of filler.

While the. method herein described, and

the form of apparatus for carrying this no ethod into effect, constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to this precise method and form of apparatus, and that changesmay be made'in either without de+ partingfrom the scope of the invention which is defined in the appended claims.

What is claimed is: a v 1. In the manufacture of paper, the method which comprises introducing a fine-grained solid water insoluble material into fibrous stock, forming a paper web from-the admixed suspension, of fine-grained material and relatively free of filler to assist in the filterfibrous stock, collecting and filtering liquid includes collecting liquidand entrained solids and entrained solids drained and removed from the web during formation, andwithdrawing a portion of the fibrous stock prior to the introduction of the fine-grained solid material thereto to form a filter mat composed practically entirely of fibers and relatively free of salted ingredients to assist in the filtering of the removed liquid.

2. In the manufacture of paper, the method which comprises beating fibrous stock, introducing filler into the fibrous stock subsedrained and removed from the web during formation and filtering the collected liquid through a filter mat formed primarily of fibrous material unmixed with any substantial proportion of filler.

In testimony whereof I hereto aflix my signature.

. JAMES J. OOONNOR.

quent to the beating, forming a traveling pa- I per web from the admixed filler and fibrous stock, collecting and filtering liquid and entrained solids drained and removed from the web during formation, and by-passing a portion of the fibrous stock prior tothe introduction of filler therein to form a filter mat composed practically entirely of fibers and ing of said removedliquid.

3. In the manufacture of paper, the method which comprises beating fibrous stock, refining such as byjordaning the stock after beating, introducing filler into the fibrousstock subsequent to therefining, forming a traveling paper web from the admixed filler and fibrous stock, collecting and filtering liquid with entrained solids drained and removed from the web during formation, and by-passing a portion of'the fibrous stock after beating and prior to the introduction of filler therein to form a filter-mat to assist in the filtering of said removed liquid.

4. In the manufacture of paper, the method which comprises passing fibrous stock in a continuous stream, continuously introducing filler into the flowing stream of fibrous stock,

forming a traveling web from the admixed filler and fibrous stock, collecting and filtering liquid with entrained solids drained and removed from the web during formation, and

withdrawing a portion of the fibrous stock prior to the introduction of the'filler therein to form a fibrous mat composed practically entirely of fibers and relatively free of filler to assist in the filtering of said removed liquid.

5. In the manufacture of paper, the method which comprises beating fibrous stock, flowing the stock after beating in a continuous stream, continuously introducing filler in controlled amounts into the flowing stock stream, forming a traveling paper web from the admixed filler and fibrous stock, collecting and filtering liquid with entrained solids drained and removed from the web during formation, and continuously withdrawing a portion of the fibrous stock after beating and prior to the introduction of the filler-therein to form a fibrous mat to assist in the filtering of said removed liquid.

a traveling web is formed from a mixture 1 of fibrous stock filler, the method'whioh iao CERTIFICATE OF CORRECTION.

Patent No. 1,868,291.* July 19, 1932.

JAMES J. O'CONNOR;

lt ishereby certified that the above numbered patent was erroneously issued to "The Mead Pulp and Paper Company, of Dayton, Ohio, a corporation of Ohio,"

whereas said patent should have. been issued to The Mead Corporation, of Dayton,

Ohio, a corporation of Ohio, as assignee by mesne assignments of the entire in ter est in said inventon as shown'by the records of assignments in this office;

and that the said Letters Patentv should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed'this 1st day of November, A. D. 1932.

M. J. oore,

(Seal) Acting Commissioner of Patents. 

